The solution to this puzzle eludes me. I can't seem to determine even 6 numbers! I've done every other xmas and very hard puzzle without problems.
What am I missing in this puzzle? I even completed the look alike puzzle on Dec 28 or 29.
Thanks for the help.

Hi,
I already solved it but anyway I have no hint where you get stucked. My method is always to fill out the candidate list for every field. I start with "1" and end with the "9". I marked the original digits with a circle for better managing the still to find digits. When all is filled out, I look for naked pairs or triplets and other relationships. When scanning the grid it often happened that
I detect a sole candidate. Also helpful is to look for single nakeds. When you only have two possiblities in a row within a block then you can remove the other same digits in that row. This is also true for columns. Here an example:

in block 9 there are two "2" in r8c8/c9 therefore you can eleminate the possible "2" in r8c1. I hope this helps a little bit. I wish you a Happy New Year! If you need more help please shout!